Distribution of depressive disorders in the elderly

BACKGROUND: The community-based mental health studies have revealed that the point prevalence of depressive disorders in the elderly population of the world varies between 10% and 20% depending on cultural situations. OBJECTIVE: To determine the median prevalence rates of depressive disorders in the elderly population of India and various other countries in the world. MATERIALS AND METHODS: A retrospective study based on meta-analysis of various study reports. SETTING: Community-based mental health surveys on geriatric depressive disorders conducted in the continents of Asia, Europe, Australia, North America, and South America. STUDY PERIOD: All the studies that constituted the sample were conducted between 1955 and 2005. Sample Size: After applying the inclusion and exclusion criteria on published and indexed articles, 74 original research studies that surveyed a total of 4,87,275 elderly individuals in the age group of 60 years and above, residing in various parts of the world were included for the final analysis. INCLUSION CRITERIA: The researchers had included only community-based cross-sectional surveys and some prospective studies that had not excluded depression on baseline. These studies were conducted on homogenous community of elderly population in the world, who were selected by simple random sampling technique. EXCLUSION CRITERIA: All the unpublished reports and unavailable or unanalyzed or inaccessible articles from the internet were excluded from the study. STATISTICAL ANALYSIS: The median prevalence rate and its corresponding interquartile range (IQR), Chi-square test, and Chi-square for Linear Trend were applied. A P value < 0.05 was considered as statistically significant. RESULTS AND CONCLUSION: The median prevalence rate of depressive disorders in the world for the elderly population was determined to be 10.3% [IQR = (4.7%–16.0%)]. The median prevalence rate of depression among the elderly Indian population was determined to be 21.9% [IQR = (11.6%–31.1%)]. Although there was a significant decrease trend in world prevalence of geriatric depression, it was significantly higher among Indians in recent years than the rest of the world.